328 Henry L. Bruner 



nasal gland in a connective tissue thickening of the nasal wall. 

 The tubules of the gland open, according to Riese, on the lower 

 angle of that thickening (»Nasenmuschel« of Riese) into the nasal 

 cavity. Seydel (45) confirmed Born's view in regard to the homology 

 of the external nasal gland of Anura and Salamandrina by his 

 discovery of the opening of the gland in the latter group, thus 

 showing that the gland has a similar function in the two groups. 



4. The Development of the Nasal Muscles and of the Glandula 

 nasalis externa. 



1) Triton. The material used in the study of the development 

 of the nasal muscles and gland consists of Triton larvae (probably 

 Triton alpestris), which vary in length from eighteen and a half to 

 thirty-one millimeters. I follow first the development of the glandula 

 nasalis externa. 



In the beginning it should be remarked that the nasal cavity 

 of the larva of Triton possesses a relatively long introductory passage. 

 From the caudal wall of this passage arises the nasal gland, whose 

 development begins, according to my material, in a specimen twenty- 

 two millimeters long. In this stage we find in the region named a 

 short epidermal invagination, which later gives rise to the entire 

 medial portion of the gland. In a specimen twenty-seven millimeters 

 long this invagination is more elongated, and a second one has been 

 added which belongs to the lateral part of the gland. A thirty-one 

 millimeter Triton larva shows the medial portion of the gland to 

 consist of four tubules and a common duct. These tubules, as well 

 as the yet single lateral tubule, reach the caudal margin of the 

 fenestra rostro-lateralis. In this stage the length of the introductory 

 passage of the nose has been greatly reduced, whereby the openings 

 of the gland are transferred to the proper margin of the nasal 

 aperture of the adult. 



The first indication of the nasal muscles I have observed in a 

 Triton larva twenty-two millimeters in length. In this stage neither 

 floor nor roof of the cartilaginous nasal capsule has reached the 

 neighborhood of the external naris. In place of these, we find, 

 above and below, a dense layer of connective tissue cells, which are 

 continuous medially with the trabecula cranii. These connective 

 tissue strata are yet surrounded by mesenchyme, which entirely 

 envelopes the introductory passage and furnishes the material for 



